Wood protection agents



4 Claims. ci. 167-38.6)

The object of the present invention is a new wood protection agent which consists of liquid, water-contaning ammonium fluoroborates with an atomic ratio of boron to fluorine of about 1:1.

The precise "composition of these ammonium fluoroborates is not known but they may, perhaps, correspond to about the formula:

wherein X X X and X, may be H, CH C H and C H OH, X X and X may be H and X, may be OH, NHZ, CH3, C2H5, C3H7 and C2H4OH, X1 and X2 may be H and X3 and X4 may be CH3, C2H5, C3H7 and CZHQOH, X, may be H and X X and X, may be CH C H C H and C H OH, and X X and X, may be CH and These compounds are obtained by the mixing of, for example, 1 mol of ammonium bifluoride with 2 mols of boric acid with the addition of some water and possibly CROSS RE't'EiiEilCE nited States Patent 0 some excess of ammonia and/or excess of ammonium compound, such as hydroxyl amine, hydrazine, methyl, dimethyl or trimethyl amine, ethyl, diethyl of triethyl amine, propyl, dipropyl or tripropyl amine, ethanol amine, diethanol amine or triethanol amine or diethyl benzyl amine. Instead of ammonium bifluoride, it is also possible to start from ammonium fluoride or from mixtures of hydrofluoric acid with ammonia or ammonium bases and, instead of from boric acid, from partially anhydrous boric acid or boric anhydride. If desired, some urea can also be added.

In comparison with the known wood protection agents, the ammonium fluoroborates are characterized by an exceptionally high solubility in water. At 20 C., about 900 parts (referred to the solid starting materials) dissolve in 100 parts of water.

This has the result that wood or wood-containing materials, such as wood shavings which are to be worked up to chip boards, take up so much wood protection agent by a single treatment with the wood protection agent, for example, by a single dipping or by painting or spraying, that they become difficultly inflammable. As a result of the fungicidal and insecticidal properties of the ammoniumfluoroborates, the wood is also substantially protected against the attack by biological destructive agencies, such as fungi and insects.

The new wood protection agent also has the further advantage that it does not affect the ability to be glued of the wood treated therewith. A special drying of the wood or of the wood-containing materials before glueing is not necessary, because of the low water content of the new wood protection agent.

As a rule, a good protection of the wood is obtained when about 50250 grams, and especially about 100*200 grams, of the wood protective agent (referred to the solid content of the agent) is applied to square meter of wood or with an addition of about 3-10 percent by weight of wood protective agent, referred to absolutely dry wood, in the case of wood materials. I

3,247,059 Patented Apr. 19, 1966 2 If desired, other known flame-proofing materials i and' wood protecting agents, sucli ifs"ammoniumsulphatej can be added to the liquid, water-containing ammonium fluoroborates.

Admittedly, boronand fluorine-containing wood protection agents are known which correspond to the general formula:

in which, consequently, the atomic ratio boron to fluorine amounts to 1:2 to 1:4 and wherein Me(I) signifies a monovalent cation. However, boron fluorides of this type are less soluble than the ammonium fluoroborates. Therefore, their concentration in the wood is, as a rule, much too low to be able to make the wood diflicultly inflammable. Their importance lies, on the contrary, in the protection of the wood against biological destructive agencies, especially when they are used together with chromates and/or arsenates so that, by a suitable choice of the additional materials, well-fixed precipitates are formed in the wood.

The ammonium fluoroborates are, with regard to their solubility in water, also significantly superior to the known phosphate combination flame-proofing agents, which are mainly ammonium phosphates with an addition of fluorides or borates or boric acid. The phosphate combinations dissolve in water at 20 C. only to an extent of about 70 parts in about 100 parts of water. In order to achieve a sufficiently difiicult inflammability of the wood with them, it is, consequently, necessary to apply several treatments of the wood with these agents. Furthermore, the wood treated with such phosphate combinations must be dried before glueing which, as mentioned, is not necessary in the case of the use of the ammonium fluoroborates according to the present invention.

The following examples are given for the purpose of illustrating the present invention:

Example 1 which contains 925 parts by weight, referred to the solid starting materials, in parts by weight of water.

Rough sawn pine planks of 20 millimeters thickness are impregnated with the solution by painting once with an amount of about grams/mi After drying, the so treated wood is difficultly inflammable and also protected against-wood-destroying fungi, such as Poria vaporaris, and against wood-destroying insects, such as the larvae of the death watch beetle.

Example 2 To a mixture of 6 mols of boric acid and 3 mols of ethanol amine there are dropped under cooling 6 mols of hydrofluoric acid as a 40 percent aqueous solution. There is obtained a highly concentrated aqueous solutionof the wood protection agent which is ready to be used for impregnating wood. For the production of laminated wooden plates, for instance, chip boards, the aforesaid fluoroborate solution is mixed with an adhesive, for instance, an urea formaldehyde resin. The working up of the wood shavings with said adhesive and protection composition to the chip board is carried out as known in the art. An interim drying of the shavings is not necessary.

I claim:

1. A method for protecting wood against insects, fungus and fire which comprises treating wood with an effective amount of a wood protecting agent comprising ammonium fluoroborates containing nitrogen, fluorine and boron in an atomic ratio of about 1:2:2, obtained by mixing corresponding proportions of a fluoro compound states selected from the group consisting of hydrofluoric acid, ammonium bifluoride, and ammonium fluoride, a boron compound selected from the group consisting of boric acid and boric acid anhydride, and a nitrogen base selccted from the group consisting of ammonia, hydroXyl amine, hydrazine, amino alkane having up to 3 carbon atoms, amino toluene, and amino ethanol, in the presence of water.

2. The method of claim 1 wherein the Wood protecting agent is used in an amount of from 50 to 250 grams per square meter of wood.

3. Wood protected against insects, fungus and fire containing an eflective amount of a wood protecting agent comprising ammonium fluoroborates containing nitrogen, fluorine and boron in an atomic ratio of about 1:222, obtained by mixing corresponding proportions of a fluoro compound selectedvfrom the group consisting of hydrofluoric acid, ammonium bifluoride, and ammonium fluoride, a boron compound selected from the groupconsisting of boric acid and boric acid anhydride, and a nitrogen 20 base selected from the group consisting of ammonia, hy-

References Cited by the Examiner UNITED STATES PATENTS 2,395,311 2/1946 Woodhouse et a1. 117-147 2,726,189 12/1955 Cook 167--38.6 2,757,121 7/1956 Fahlstrom 16738.6 2,799,556 7/1957 Sullivan et a1. 2359 2,948,641 8/1960 McCluer 10615 3,071,618 1/1963 Pinson 260-567.6 3,076,835 2/1963 Kay et a1. 260462 3,119,654 1/1964 Cunningham 2359 3,169,983 2/1965 Hunter 260-462 JULIAN S. LEVITT, Primary Examiner. 

1. A METHOD FOR PROTECTING WOOD AGAINST INSECTS, FUNGUS AND FIRE WHICH COMPRISES TREATING WOOD WITH AN EFFECTIVE AMOUNT OF A WOOD PROTECTING AGENT COMPRISING AMMONIUM FLUOROBORATES CONTAINING NITROGEN, FLUORINE AND BORON IN AN ATOMIC RATIO OF ABOUT 1:2:2, OBTAINED BY MIXING CORRESPONDING PROPORTIONS OF A FLUROR COMPOUND SELECTED FROM THE GROUP CONSISTING OF HYDROFLUORIC ACID, AMMONIUM BIFLUORIDE, AND AMMONIUM GLUORIDE, A BORON COMPOUND SELECTED FROM THE GROUP CONSISTING OF BORIC ACID AND BORIC ACID ANHYDRIDE, AND A NITROGEN BASE SELECTED FROM THE GROUP CONSISTING OF AMMONIA, HYDROXYL AMINE, HYDRAZINE, AMINO ALKANE HAVING UP TO 3 CARON ATOMS, AMINO TOLUENE, AND AMINO ETHANOL, IN THE PRESENCE OF WATER. 